James w



(No Model.)

J. W. EASTON.

DYNAMO ELECTRIC GENERATOR.

No. 357,705. Patented Feb. 15, 1887.

5 James Wlaszam,

1 g @51 'Mo/ GHQ: 013d N. PETERS. Pnowuum m hm. Washington. a. c.

UNITED STATES PATENT OFFICE.

JAMES \V. EASTON, OF NEW YORK, N. Y.

DYNAMO-ELECTRIC GENERATOR.

SPECIFICATION forming part of Letters Patent No. 357,705, dated February 15, 1887.

Application filed April 13, 1886.

T0 aZZ whom, it may concern:

Be it known that I, James W. EASTON, a subject of the Queen of Great Britain, residing in New York, in the county ofNew York, and in the State of New York, have invented certain new and useful Improvements in Dynamo- Electric Generators, of which the following is a specification.

The invention relates to the construction of dynamo-electric machines and an organization of circuits adapted to operate translating devices requiring currents of greatly-differing potential, such, for instance, as electric-arc lights and incandescent electric lights.

The object of the invention is to provide a a machine adapted to automatically produce currents of the character required upon two different systems of circuits and to cause the currents supplied to one system of translating devices to be entirely selfregulating, and also to so operate as to maintain a constant field of force for the production of both classes of our- I rents, and at the same time render it possible to produce the currents required in each system independently of the other, so that any accident which might render either system inoperative shall not prevent the operation of the other system.

The invention is especiallyapplicable to are and incandescent electric-1i ghting systems, and will for convenience be described in connection therewith, although it has other uses.

In general terms the invention consists in organizing the apparatus substantially as follows: An ordinary dynamo-electric generator is provided with a system of circuits for operating the arc lights in the usual manner. Upon the armature-shaft of this generator there is carried a subsidiary armature, for which a field-magnet is provided by extending polar projections from the field-poles of the main armature. The armature-coils of the subsidiary armature are connected in series with fieldcoils applied to these polar extensions, and the incandescent electric lights are included in multiple are between the conductors leading from the opposite poles of the subsidiary armature. The two supply-conductors for the incandescent lights are also further connected by additional conductors with the respective terminals of the main field-magnet coils. These maintain the main field of force.

(No model.)

conductors serve, in connection with the coils of the subsidiary armature, as a shunt-path around the coils of the main field, should the current generated by the main armature become too great.

The parts are so organized that the main armature will supply the currents necessary to operate the system of arc lights, while the subsidiary armature supplies the incandescent lights. It is well known that in arc-light systerns as usually organized a constant current is required, while in incandescent systems a constant difference of potential is necessary. The main armature is therefore provided with any ordinary means for insuring a current as constant as may be required to maintain the arc lights steady and working properly, and this current should be the proper current to field-magnet is of practically constant resist ance, and is connected, as already stated, by conductors of very small resistance to the conductors of the constant potential circuit or system. From these conditions it follows that the current flowing through the coils of the main-field magnet, and consequently its mag netic force, is always practically constant, regardless of the strength or absence of the main current, unless the circuit of constant potential should become interupted,'in which case the field-magnet becomes an ordinary series field-magnet, and is wholly dependent upon the main current. Owing to the fact that the main field-magnet has a constant magnetizing force as long as the source of constant potential is operative, and owing to the regulating power of the coils on the derived or subsidiary polar extensions, the subsidiary armature will preserve a constant difference of potential under all ordinary circumstances without any attention. Should the normal relations be disturbed-as, for instance, should the current from the main armature increase beyond the proper amountthe excess of current will traverse the coils of the subsidiary armature and thus be shunted from the main field-magnet. Should the circuit of the subsidiary armature be interrupted, the main armature will still continue to produce the current required upon the are system of circuits, because the current from the main armature should be the proper current to operate the are system; and like wise should the current operating the arc lights be interrupted the subsidiary armature would continue to supply the current necessary for the incandescent lights.

The accompanying drawing is an elevation of a machine showing in diagram an organization of circuits illustrating the invention.

Referring to the figures, A represents the armature of a dynamo-electric generator. The armature is mounted upon a shaft, B, and revolves between the pole-pieces O and G These pole-pieces receive their magnetization from cores F F and F F which are respectively surrounded by magnetizing-coils G G and G G". The armature is provided with a collector,H,provided with two contact-brushes, i i and these brushes are respectively connected by conductors]. and 2, through the magnetizing-coils, and with a main circuit, L, including the series of are or other translating devices K K. The parts are so organized that while the coils will produce sufficient magnetism in the pole-pieces for producing the required current, yet the pole-pieces are preferably not magnetized to saturation.

Upon the same armature-shaft B with the armature A there is carried a subsidiary armature, a. This is provided with pole-pieces c c", which are derived from the pole-pieces O and 0 being connected therewith by arms 0 and c of magnetic material. The arms 0 and c are wound with magnetizingcoils g and g and are connected in circuit with the coils of the armature (t in such manner that currents therefrom will produce in the pole-pieces c and c magnetism of the same character as that which they receive by induction from the polepieces 0 G The armature (tlS provided with a collector, h, provided with collector-brushes if and t. The brush t is connected by a conductor, 3, through the coils g and and with a conductor, Z,'leading to the system of incandescent electric lights k 70. These lights are connected in multiple are between the conductor Z and a return-conductor, 1*, leading to the brush i.

During the normal operation of the machine the currents necessary to operate the arc lights K K are derived from the armature A, and the currents of constant potential required for operating the incandescent lights is are derived from the armature a. The latter armature and. the subsidiary tield-magnet coils g and are constructed to maintain a constant difference of potential between the conductor Z and Z,- and this system serves also to maintain the field of force of the main armature constant. For this latter purpose a conductor, 5, leads from the conductor l to one terminal of the main field-magnet coils at a point, 6, and a conductor, 7, leads from a conductor, 1*, to a point, 8, at the other terminal of the main field-magnet coils. These conductors form for the currents produced by the armature A a path through the armature a, together with its field-magnets, or through the translating devices 7c in case the current increases beyond that necessary to maintain the main field. Should, therefore, the current produced by the armature A exceed that required through the main field-magnet coils, and should the resistance offered by these coils of the main field-magnet exceed that of the shunt through the constant potential circuit, then more or less current will be diverted around the main field-magnet coils. In this manner the fields of force for both armatures will be maintained constant and the required results attained.

I claim- 1. The combination, substantially as here inbefore set fortlnwith a dynamo-electric generator, of a subsidiary armature secured to the shaft thereof, additional pole-pieces de rived from the main field-magnet of the generator and applied to said subsidiary armature, independent field-magnet coils connected with the subsidiary armature-coils and applied to said derived poles, and conductors connecting the circuit of the main with the circuit of the subsidiary armature.

2. The combination, with a dynamo'elcctric generator, of a subsidiary armature carried upon the shaft thereof, a field-magnet for the same derived from the field-magnet of the main armature, field-1nagnet coils applied to the subsidiary field-magnet, and conductors leading from the respective terminals of the subsidiary armature-coils to the respective terminals of the main field'magnet coils.

3. The combination, substantially as hereinbefore set forth, with a revolving shaft, of two armatures secured thereto, two field-magnets for the same, two sets of magnetizingcoils respectively applied to said field-mag nets, two systems of translating devices respectively included in the circuits of said armatures, and conductors uniting said circuits with each other.

at. In a dynamo-electric machine, the combination, with a main field-magnet, of a subsidiary field-magnet derived therefrom, and magnetizing-conductors serving to regulate the magnetization of said subsidiary field-magnet.

5. In a dynamo-electric machine, the combination, with a main magnetizing iield-magnet, of asubsidiary field-magnet derived therefrom, inagnetizing-conductors serving to regulate the magnetization of said subsidiary fieldmagnet, and a secondary armature in said subsidiary field-magnet.

In testimony whereof I have hereunto subscribed my name this 25th day of March, A. D. 1886.

JAMES W. EASTON.

Witnesses:

THOS. TRYON, CHARLES A. TERRY.

IIO 

